Field of the Invention
The present invention relates to an X-ray fluoroscopic device and a method of X-ray fluoroscopy using the same in order to specify the position of the marker or the specific area by continuously detecting and collecting images including the marker indwelled inside the subject's body or the specific area of the subject with an X-ray detector.
Description of the Related Art
The radiation relative to a radiation therapy, in which the radiation including an X-ray and an electron beam and so forth is irradiated to the affected area including a tumor and so forth, must be accurately irradiated to the affected area. Nevertheless, in some cases, not only the subject unintentionally moves the body thereof, but also the affected area per se moves. For example, a tumor near the lung largely moves depending on breathing. Accordingly, a radiation therapeutic device comprising the system, in which the X-ray fluoroscopic device detects the position of a metal marker in-place near the tumor and then the therapeutic radiation to be irradiated is controlled thereby, is disclosed (refer to Patent Document 1.)
According to such radiation therapeutic device, the fluoroscopic image is collected by detecting the marker indwelled in the body using the first X-ray fluoroscopic mechanism comprising a first X-ray tube and a first X-ray detector and the second X-ray fluoroscopic device mechanism comprising a second X-ray tube and a second X-ray detector and then a three-dimensional position information is obtained by utilizing the two-dimensional fluoroscopic image based on the first X-ray fluoroscopic mechanism and the two-dimensional fluoroscopic image based on the second X-ray fluoroscopic mechanism. And, the real-time three-dimensional position information of the marker is calculated by performing the continuous X-ray fluoroscopy so that the marker of the region along with move can be detected with a high degree of accuracy, and radiation of the therapeutic radiation is controlled based on the position information of the marker so that the irradiation of the radiation corresponding to the move of the tumor can be performed with a high degree of accuracy, accordingly. When the position information of the marker is obtained, the template matching utilizing the template image is performed.
FIG. 11 is an explanatory drawing illustrating the conventional template matching operation.
First of all, a template corresponding to the marker M is prepared for performing the template matching. In such case, the image 70 of the subject including the marker M is imaged. And, the template image 71 is obtained by extracting the marker M region from the image 70. On performing fluoroscopy, the template matching is conducted using the template image 71 relative to the region 73 where the marker M exists relative to the image 72 of the subject, which is collected at a constant framing rate, so that the position of the marker M can be identified.
The marker M used in such radiation therapeutic device has conventionally a sphere-like shape therefor. Specifically, when the template matching is performed relative to the image 72 of the subject, which is collected at a constant framing rate, utilizing the template image 71, if such spherical marker M is used, the imaging of the marker M from any directions provides a circle image so that the template matching can be performed effectively with just preparing only the marker having a circular shape as a template image.
On the other hand, it is problematic that the spherical marker M is hardly indwelled inside the body of the subject. Specifically, when a spherical marker M is employed, it can be slippery against and hardily hooked to the viscera due to the shape per se thereof so that even once it is indwelled inside the body, it will likely drop out from the indwelled region in-place. Accordingly, a number of markers M are indwelled inside the body in advance while predicting that such drop-out will take place and then the marker M that has not dropped out is being utilized, in some cases. Nevertheless, in such case, it is problematic that a wasteful expense may be incurred in order to indwell a number of markers M and the longer surgery time for indwelling may burden the subject.
Consequently, a coil-type marker and non-spherical marker recently have been proposed (refer to Patent Document 2 and Patent Document 3.) According to these devices of Patent Document 2 and Patent Document 3, a template matching is performed by utilizing the image including the marker.